In the absence of a substantial brick-and-mortar presence where one could actually hear products, audio forums become something of a replacement while adding a breadth of access that is now worldwide. "I cannot find a place to hear this xyz product, have you heard it?"
The impact of WBF forums is that all the many people who make genuine contributions along with those who kibbitz, along with all the non-members who read-only make up a very large audience that attracts advertisers to this broad group made available to them to sell their wares.
Only a handful of sites can exist without advertising. The forum is a sales platform that charges for all advertising, with dealers and manufacturers buying ads and paying fees to the forum just to be here if they make any comment about having products for sale. Dealers and manufacturers may not advertise if the audience is small or if they do not find direct benefit (sales, exposure) from participating. Some successful audio forums such as this one will plow some profit back into the site to make it even better in hopes of attracting larger memberships and readers.. While we are told it is a privilege for us to be here, without us the enterprise will be smaller or not at all. It is a collection of quasi-symbiotic relationships.